Two-way broadcasting and receiving method with time limit and/or limit data

ABSTRACT

A two-way broadcasting system and method by which the amount of accesses from the reception side can be controlled with certainty by the broadcasting side and a receiving apparatus for use with the method wherein, information of a reply to a question from a broadcasting side is transmitted from a reception side to the broadcasting side by way of a telephone line. Each receiving apparatus on the reception side has individual identification information, and the broadcasting side broadcasts information regarding a reply destination and telephone call origination limiting information for limiting transmission of the information of a reply in a multiplexed condition with a broadcasting signal from the broadcasting side. On the reception side, transmission of the information of a reply to the reply destination is inhibited when the identification information peculiar to a receiving apparatus on the reception side satisfies a condition provided by the telephone call origination limiting information for inhibiting a telephone call origination of a reply to the reply destination.

This is a division of application Ser. No. 08/360,101 filed Dec. 20,1994 now U.S. Pat. No. 5,682,599.

FIELD OF THE INVENTION

This invention relates to a two-way broadcasting method suitable forresponding by way of a telephone line and a receiver apparatus for usewith the two-way broadcasting method as well as a two-way broadcastingmethod wherein the broadcasting station side provides a two-way program,or including information regarding a reply destination whereas thereceiver side transmits response information of a user to the two-wayprogram to the reply destination by way of a telephone line and atwo-way broadcast receiving apparatus for use with the two-waybroadcasting method.

BACKGROUND OF THE INVENTION

In a telephone network at present, if accesses occur in a concentratedmanner at once upon a certain local area, then an overcrowded conditionof telephone lines occurs, resulting in failure or difficulty inconnection of a telephone call. The overcrowded condition of telephonelines occurs when telephone calls and requests for a telephone calloccur in such a concentrated condition upon particular telephone linesthat they exceed the processing capacity of the telephone lines. Forexample, it frequently occurs that telephone calls to or from a districtin which a disaster such as an earthquake has occurred are not connectedor connected seldomly. This arises not because a telephone network or anequipment of a central office has been destroyed by the disaster butbecause telephone calls for inquiring after safety of inhabitants in thedistrict in which the disaster has occurred, occur in a concentratedmanner at once from other districts or telephone calls from inhabitantsin the district for notifying safety of them to the other districtsoccur in a concentrated manner at once.

In order to eliminate such an overcrowded condition of telephone lines,for example, a company which accepts reservations of tickets or sellstickets using telephone lines conventionally takes such a countermeasureas to prepare an equipment almost corresponding to a central office of atelephone system. By the way, a participation show by accessesed by wayof telephone lines is held by television broadcasting or radiobroadcasting. Such participation show is broadcast, for example, as atelevision shopping program, a questioning program or a participationtype quiz program. In the participation shown, the broadcasting sideannounces a telephone number for reception of a response or displayssuch telephone number in a superimposed condition on a screen for asuitable period of time to inform a destination for a response to thereceivers whereas a receiver responds by way of a telephone call orfacsimile.

However, a participation show of the type described above has a problemin that, as the appealing degree of the program increases, the number ofaccesses of telephone lines of receivers increases so that the telephonelines may be over-crowded. In particular, telephone calls and requestsfor a telephone call occur in such a concentrated manner upon particulartelephone lines that they exceed the processing capacity of thetelephone lines, resulting in failure or difficulty in connection oftelephone calls.

For example, in shopping by way of television, a large number ofsubscribers or viewers can participate as purchasers of commodities, andaccordingly, a large number of articles can be sold. However, when somecommodity is appealing in that there is some limitation in quantity ofcommodities to be sold or the price is very low and a large number ofsubscribers want to purchase the commodity, a large number of accessesfrom subscribers who want to purchase the commodity may be received sothat the telephone lines to be used for proposals for purchase may beovercrowded.

In such shopping by way of television or the like, responses fromsubscribers are received in a concentrated condition immediately afterstarting of reception of responses and immediately before ending ofreception of responses as seen in FIG. 12, and there is a tendency inthat the telephone lines are crowded or overcrowded at such concentratedtime zone. This occurs since subscribers who want to have a proposal forpurchase accepted promptly originate telephone calls in a concentratedcondition in the time zone immediately after starting of acceptance of aresponse, but subscribers who want to purchase but have been suspendedto purchase originate telephone calls in a concentrated condition in thetime zone immediately before the reception of a response is ended. Onthe other hand, in the case of a quiz program which requires fastdepression or activation of a switch or the line, that is thefirst-come, first served type, responses from subscribers occur in aconcentrated manner upon a time zone immediately after the time instantof starting of reception of a response as seen in FIG. 13 since they tryto transmit a response as early as possible. In contrast, in the case ofa quiz program of the deliberation type which requires muchdeliberation, responses from subscribers occur in a concentrated mannerupon another time zone immediately before the time instant of the end ofthe reception of a response as seen from FIG. 14 since they try totransmit an answer as accurate as possible. In either case, subscribersof the two-way television broadcast are many and unspecific persons, andit is very liable that the telephone lines are so crowded that telephonecalls cannot be connected readily or are overcrowded. In such a quizprogram as described above, an access answer is accepted in a "firstcome, first served" fashion or a limit time for reception of a reply isdetermined. However, with the conventional responding method describedabove wherein telephone lines are used, if telephone calls and requestsfor telephone calls occur in such a concentrated manner upon particulartelephone lines that they exceed the processing capacity of thetelephone lines, telephone calls are not connected quickly, anddepending upon a response timing, a later telephone access may beconnected earlier, or although a response is originated within the limittime, it may be received by the reply destination but outside the limittime. Or, since a preferential order of telephone calls may bedetermined on the switching office side due to a local areacharacteristic, where a conventional method wherein a telephone callconnected first is received is employed, responses from subscribers byway of telephone lines cannot be processed fairly.

While it is a possible countermeasure to provide an equipmentcorresponding to a central office as in a ticket reservation systemdescribed hereinabove, the countermeasure not only requires a high costbut also may cause, in the case of a highly-rated program, a crowded orovercrowded condition of telephone lines due to concentration ofresponses. In order to eliminate the problem of an overcrowded conditionof telephone lines, the broadcasting station side often designates, forexample, the digit of the last figure for telephone numbers ofsubscribers to request restriction of telephone call origination inorder to limit participation of subscribers.

Since the request, however, relies upon the good intentions ofsubscribers, it does not have an absolute effect and does not disableaccessing of a subscriber whose telephone number is not permitted forparticipation.

By the way, an overcrowded condition of telephone lines is caused sincea load is applied not only where telephone lines are actually connectedbut also where telephone lines are being connected. In particular, if atelephone receiver or earphone is picked up into an off-hook condition,the capacity for one telephone line is occupied, and accordingly, forexample, if telephone receivers of all telephone sets in a districtcontrolled by a certain central office are picked up at a time, thetelephone lines are put into an overcrowded condition. Such anovercrowded condition may occur when utilization of telephone sets in acertain district occurs suddenly due to, for example, the occurrence ofa local disaster or the like. However, it is considered that, in aparticipation show, the problem of an over-crowded condition seldomoccurs with a central office on a telephone call origination side, thatis, on a subscriber side, unless the program rating is particularlyhigh. In contrast, it is considered that, in the case of a broadcastingprogram of the participation type, the problem occurs with a centraloffice which controls telephone lines on the broadcasting station sidewhich is the response reception side. In particular, there is a problemin that, even if telephone lines are not connected actually, a largenumber of requests for use of telephone lines to be connected are madein a concentrated condition upon the telephone lines of a single centraloffice, and even if the broadcasting station itself does not receivetelephone calls, application of a load to the telephone lines cannot beprevented unless origination of telephone calls from subscribers isrestricted.

SUMMARY OF THE INVENTION

It is an object of the present invention to provide a two-waybroadcasting method by which the amount of accesses from the receptionside can be controlled with certainty by the broadcasting side and areceiving apparatus for use with the two-way broadcasting method.

It is another object of the present invention to provide a two-waybroadcasting method which can prevent a crowded or overcrowded conditionof telephone lines caused by transmission of responses from subscribersof a two-way program and a receiving apparatus for use with the two-waybroadcasting method.

It is a further object of the present invention to provide a two-waybroadcasting method which allows fair processing of responses fromsubscribers of a two-way program and a receiving apparatus for use withthe two-way broadcasting method.

A multiplex broadcast system is shown, for example, in U.S. applicationSer. No. 08/344,757 by Hitoshi Yoshinobu, which was filed on Nov. 23,1994, the disclosure of which is hereby incorporated by reference.

In order to attain the objects described above, according to an aspectof the present invention, there is provided a two-way broadcastingsystem and method wherein information representing a reply(reply data)to a question from a broadcasting side is transmitted from a receptionside to a broadcasting side by way of a telephone line, wherein eachreceiving apparatus on the reception side has individual identificationinformation, or identification data, associated therewith. Thebroadcasting side broadcasts information representing a specified replydestination (destination data) and telephone call origination limitinginformation (limit data) for limiting transmission of reply (data), in amultiplexed condition with a broadcasting signal from the broadcastingside. On the reception side, transmission of the information of a reply(reply data) to the reply destination is inhibited when theidentification information peculiar to (associated with) a receivingapparatus on the reception side satisfies a condition provided by thetelephone call origination limiting information (limit data) forinhibiting a telephone call origination and transmission of reply datato the specified reply destination.

With the two-way broadcasting method, only those receiving apparatuswhich do not satisfy the condition provided by the telephone callorigination limiting information are enabled or allowed to access thespecified reply destination to transmit reply data there to.Consequently, the amount of accesses from the reception side can becontrolled with by way of the telephone call origination limitinginformation by the broadcasting side. This destination data and limitdata can be transmitted as sub-broadcasting information associated witha main broadcast signal.

Preferably, sub broadcasting information relating to a program such asdata for accessing to the two-way broadcast or data for reservation ofthe program is transmitted using a DTMF signal within an audio signalband and is broadcast in a multiplexed condition with a mainbroadcasting audio signal. In this instance, on the reception side, thesub broadcasting information can be received and decoded readily using aDTMF decoder. Preferably, on the reception side, the sub broadcastinginformation is stored, after decoding, into storage means. Where the subbroadcasting information is stored into storage means, it isunnecessary, for example, to take notes of an access number, for examplea telephone number, to a participation show, which is convenient to theuser of the receiving apparatus of the reception side.

On the broadcasting side, an encoder on the market can be used as anencoder for a DTMF signal and may be used to mix a DTMF signal with amain broadcasting audio signal. Accordingly, the burden to thebroadcasting side is light compared with that in the character multiplexbroadcasting system. On the other hand, also on the reception side, aDTMF signal can be extracted from a demultiplexed signal of an audiodemultiplexer using a DTMF decoder, and also the receiving apparatus canbe constructed at a low cost. Besides, since a DTMF signal is decodedfrom an audio signal, a reception decoder need not be changed dependingupon the broadcasting method as in the case of the character multiplexbroadcasting system.

Where decoded sub broadcasting information is stored into storage means,the thus stored sub broadcasting information can be used for anautomatic response (automatic dialing) to a two-way program or forreservation of a program.

The identification information (identification data) associated witheach receiving apparatus on the reception side may be a product modelnumber, or serial number of the receiving apparatus; or it may be atelephone number associated with a user of the receiving apparatus.

Where the broadcasting signal is a main audio signal, the informationregarding the reply destination and the telephone call originationlimiting information may be broadcast in the form of a multi-frequencysignal, which includes a combination of a plurality of frequenciesselected one by one from a plurality of frequency groups in an audiosignal band, in a multiplexed condition with the main audio signal.According to another aspect of the present invention, there is provideda two-way broadcast receiving apparatus which comprises use input meansfor inputting command information which may include a reply to aquestion or the like (reply data) from a broadcasting side, transmittingmeans for transmitting the inputted reply information (reply data) tothe broadcasting side by way of a telephone line, reproduction means forreproducing (or extracting) information regarding a reply destination(destination data) multiplexed with a reception signal, or broadcastsignal, and telephone call origination limiting information (limit data)multiplexed with the reception signal for limiting transmission of thereply information, storage means for storing the information regardingthe reply destination and the telephone call origination limitinginformation reproduced by the reproduction means, holding, or storage,means holding, or storing, identification information (identificationdata) peculiar to, or associated with, the receiving apparatus, adiscrimination means, or comparator, for comparing the telephone callorigination limiting information and the identification informationpeculiar to the receiving apparatus with each other to discriminatewhether or not a telephone call origination for the reply from thereceiving apparatus is permitted, and means for inhibiting, when theresult of discrimination by the discrimination means proves that atelephone call origination from the receiving apparatus is notpermitted, transmission of the reply information to the replydestination.

Since the two-way broadcast receiving apparatus has the constructiondescribed above, the two-way broadcasting method of the presentinvention can be executed on the two-way broadcast receiving apparatus.

The identification information peculiar to the receiving apparatus maybe a product number of the receiving apparatus or a telephone number ofa receiving user.

According to a further aspect of the present invention, there isprovided a two-way broadcasting method wherein a two-way broadcastincluding information regarding a reply destination is provided from abroadcasting station side, and information of responses of users to thetwo-way program is transmitted from a reception side to the replydestination by way of telephone lines, wherein each receiving apparatusof the reception side has identification information peculiar thereto,and when a responding operation to the two-way program is performed by auser of a receiving apparatus of the reception side, a transmission timeinstant is set in accordance with the identification information and theresponse information is transmitted to the reply destination at the thusset transmission time instant.

In the two-way broadcasting method, when a user of a receiving apparatusperforms an operation to respond to a two-way program, a transmissiontime instant different from the time instant at which the respondingoperation is performed is set in accordance with identificationinformation peculiar to the receiving apparatus, and the responseinformation is transmitted at the transmission time.

Generally, identification information peculiar to a receiving apparatusis random information and also users who operate to respond performtheir operations at random. Consequently, transmission times set inaccordance with such random identification information are notconcentrated but dispersed. Consequently, an otherwise possible crowdedor overcrowded condition of telephone lines can be prevented. Inparticular, when many and unspecified subscribers intend to transmit, inresponse to a request for a response provided to many and unspecifiedsubscribers by a broadcasting program as in shopping by way oftelevision or two-way broadcasting, response information by way oftelephone lines, transmissions of such response information can bedispersed without being concentrated temporarily. This can be achievedby way of a two-way broadcasting method in which transmission ofresponse information is not performed simultaneously with a respondingoperation but the transmission time instant for the response informationis made different from the time instance of the responding operation sothat transmissions of response information from many and unspecifiedsubscribers may be dispersed. Consequently, the load applied totelephone lines is reduced to prevent an overcrowded condition of thetelephone lines.

Preferably, the response information to be transmitted to the replydestination includes information regarding a point of time at which theresponding operation is performed so that the point of time of an actualresponding operation can be identified accurately by the replydestination, and consequently, transmissions of responses, which areotherwise concentrated in a two-way broadcast with which the respondingoperation time is critical as in a quiz program of the "first come,first served" type, can be dispersed and the reply destination canprocess such response information fairly.

The two-way broadcasting method may be constructed such that, uponbroadcasting of the two-way program, the broadcasting station sidebroadcasts the information regarding the reply destination and theinformation regarding a response including a limit time to responsesfrom users in a multiplexed condition with a broadcasting signal, and onthe reception side, when a responding operation to the two-way broadcastis performed within the response limit time by a user of a receivingapparatus, a transmission time instant is set within a time rangeincluding a time outside the limit time in accordance with theidentification information and then response information includinginformation regarding a point of time at which the responding operationis performed is transmitted to the reply destination at the thus settransmission time instant. With the two-way broadcasting method, whenthere is a limit time set for responses, transmissions of responseswhich are concentrated immediately prior to a limit time ending timeinstant are dispersed also to a time after the end of the limit time.Accordingly, transmissions of responses which are concentrated upon ashort time zone immediately prior to the limit time ending time instantcan be dispersed over a longer interval of time, and accordingly, thedispersion effect is high.

According to a still further aspect of the present invention, there isprovided a two-way broadcast receiving apparatus which transmits aresponse of a user of the receiving apparatus to a two-way programprovided from a broadcasting station side is transmitted to apredetermined reply destination by way of a telephone line, comprisinginputting means for inputting information of a response to the two-wayprogram, transmission means for transmitting the thus inputted responseinformation to the reply destination of the broadcasting station side byway of a telephone line, a time circuit for providing time instantinformation, storage means for storing identification informationallocated to the receiving apparatus, and transmission time settingmeans for setting a time instant at which the response information is tobe transmitted in accordance with the time instant information from thetime circuit and the identification information, the responseinformation being transmitted to the reply destination by thetransmission means when the time instant set by the transmission timesetting means comes.

Preferably, the two-way broadcast receiving apparatus further comprisesmeans for inserting information into the response information regardinga point of time at which the responding operation is performed into theresponse information.

Preferably, the two-way broadcast receiving apparatus further comprisesextraction means for extracting limit time information of responses tothe two-way program multiplexed in a broadcasting signal, means forstoring the thus extracted limit time information, means for insertinginformation regarding a point of time at which the responding operationis performed into the response information, and discrimination means fordiscriminating from the time information from the time circuit whetheror not the time instant at which the responding operation is performedis within a predetermined time prior to a response ending time instantwhich is determined from the limit time to responses, the transmissiontime setting means setting, when the result of discrimination from thediscrimination means proves that the time instant at which theresponding operation is performed is within the predetermined time priorto the response ending time instant, a transmission time instant for theresponse information within a predetermined time after the responseending time instant. Since the two-way broadcast receiving apparatus hasthe construction described above, the two-way broadcasting method of thepresent invention can be executed with certainty on the two-waybroadcast receiving apparatus.

The above and other objects, features and advantages of the presentinvention will become apparent from the following description and theappended claims, taken in conjunction with the accompanying drawings inwhich like parts or elements are denoted by like reference characters.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a block diagram of a two-way broadcast receiving apparatus towhich a two-way broadcasting method according to the present inventionis applied showing a first preferred embodiment of the presentinvention;

FIG. 2 is a diagrammatic view illustrating a DTMF signal used in thetwo-way broadcasting method of the present invention;

FIG. 3 is a table illustrating criteria for sending out conditions of aDTMF signal;

FIG. 4 is a flow chart illustrating general operation of the receivingapparatus of the present invention for receiving sub broadcastinginformation by way of a DTMF signal;

FIG. 5 is a flow chart illustrating details of processing at a certainstep of the flow chart of FIG. 4;

FIG. 6 is a flow chart illustrating an operation of the receivingapparatus of FIG. 1 for responding to a two-way program;

FIG. 7 is a block diagram of another two-way broadcast receivingapparatus to which another two-way broadcasting method according to thepresent invention is applied showing a second preferred embodiment ofthe present invention;

FIG. 8 is a flow chart illustrating processing of the receivingapparatus for dispersing a transmission time instant of responseinformation;

FIG. 9 is a diagram illustrating dispersion of a transmission timeinstant of response information

FIG. 10 is a diagrammatic view illustrating an example of responseinformation used in the receiving apparatus of FIG. 7;

FIG. 11 is a diagrammatic view illustrating a manner of multiplexing andcontents of information relating to a program; and

FIGS. 12, 13 and 14 are diagrams illustrating different examples of thefrequency of responses from subscribers of a two-way program.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Before a two-way broadcasting method and a receiving apparatus for usewith the two-way broadcasting method according to the present inventionare described, a DTMF (Dual Tone Multi-Frequency) signal which is usedto transmit sub broadcasting information such as information for aresponse to be sent to the subscriber side in a two-way program will bedescribed first.

In particular, the broadcasting station side constructs informationrelating to a program as sub broadcasting information into a signal ofthe DTMF signal form, multiplexes (mixes) the signal with a mainbroadcasting audio signal and broadcasts the multiplexed signal. On theother hand, the subscriber side demultiplexes the DTMF signal from thereceived broadcasting audio signal, decodes the DTMF signal to reproducethe information relating to a program, stores the information into amemory and utilizes the information in telephone communication with aservice station such as the broadcasting station. The DTMF signal willbe described with reference to FIGS. 2 and 3. DTMF Signal

The DTMF signal system is an audio band signal system wherein two tonesof a group (low group) of low frequencies and another group (high group)of high frequencies are sent simultaneously. Each of the groups of lowfrequencies and high frequencies includes a tone of four audio bandfrequencies which have no articulation relationship between any two ofthem.

In the DTMF signal system, the four frequencies of the low group are,for example, 697 Hz, 770 Hz, 852 Hz and 941 Hz, and the four frequenciesof the high group are, for example, 1,209 Hz, 1,336 Hz, 1,477 Hz and1,633 Hz. The frequencies of the low group and the high group arecombined in a one-by-one relationship to obtain different DTMF signalsof 16 different combinations (each of such DTMF signals will behereinafter referred to as function signal), and the DTMF signals areallocated to push-buttons "0" to "D" disposed in four rows and fourcolumns of a telephone set as seen in FIG. 2.

In telephone communications, only 12 of the function signals of thetotaling 16 combinations for a DTMF signal are generally used for asignal of a subscriber's address (telephone number). In particular, thefunction signals of the 12 combinations correspond to the numerals "0"to "9", which are used for ten keys of a telephone set, and the symbols"*" and "#". The function signals corresponding to the characters "A","B", "C" and "D" indicated by broken lines in FIG. 2 are not universallyused in Japan, but are used only for data transmission which makes useof push-button (PB) dialing.

When a telephone line is to be selected in accordance with a telephonenumber using such DTMF signal, the sending out conditions are prescribedas seen in FIG. 3.

Due to a combinations of two frequencies and the sending out conditionsdescribed above, any DTMF signal is seldom produced in nature and can bedistinguished definitely from natural sound such as a voice of a humanbeing. Accordingly, the DTMF signal can be broadcast in a multiplexed(mixed) condition with an ordinary broadcasting audio signal and can bedemultiplexed comparatively readily on the reception side. Incidentally,the DTMF signal is utilized also in a multi-function telephone and canbe used, in response to operations of push-buttons of a telephone set ofthe push-button type from a remote location, to reproduce a messagerecorded in absence by a home telephone answering machine, record orreproduce a response message recorded in absence or erase a recordedmessage.

In the embodiment of the present invention described below, on thetransmission side, that is, on the broadcasting station side, among thefunction signals signifying "A", "B", "C" and "D" which are not used forselection of a PB telephone line as described above, the functionsignals of "A", "B" and "C" are used for transmission startinginformation for sub broadcasting information while the function signalof "D" is used for transmission ending information upon transmission ofsub broadcasting information.

Since three different kinds of transmission starting information areprovided, in the embodiment described below, three different kinds ofsub broadcasting information can be transmitted. In particular, each ofthe three kinds of sub broadcasting information is delineated, whenbroadcast, by one of the function signals of "A", "B" and "C" and thefunction signal "D".

For example, information regarding a response access to a two-wayprogram, for example, sub broadcasting information such as a telephonenumber (reception telephone number) of a reply access destination and atransfer rate, is transmitted between the function signal of "A" astransmission starting information and the function signal of "D" astransmission ending information. Further, for example, sub broadcastinginformation regarding environmental setting such as response limitinginformation for the responding side and setting of the present timeinstant is broadcast in a multiplexed condition as a signal interposedbetween the function signal of "B" and the function signal of "D", andinformation regarding clearing of reception data is broadcast in amultiplexed condition as a signal interposed between the function signalof "C" and the function signal of "D".

Then, on the subscriber side, numerical and/or symbol data interposedbetween one of the function signals "A", "B" and "C" as transmissionstarting information and the function signal of "D" as broadcastingending information are regarded as a sub broadcasting data train(information set) and are stored distinctly into a predetermineddifferent storage area of a memory as hereinafter described.

For example, when accessing for 120 minutes at the transfer rate of 300bps to a reception telephone number of 0990-1234-1234 is to be permittedto telephone subscribers whose interactive television specificationversion is 00, as information regarding a response access, subbroadcasting information of such a data train constituted from differentfunction signals for a DTMF signal as

    00#120#0990*1234*1234

is transmitted in a multiplexed condition with a main broadcasting audiosignal in an interposed relationship between the function signal of "A"and the function signal of "D". Of the data train here, the first "00"represents that the interactive television specification version is 00(transfer rate: 300 bps), and the numeric data following the symbol #"at the second occurrence represents the reception telephone number.

On the other hand, when it is tried to permit subscribers whoseinteractive television specification version is 01 to access to atelephone number 0990-1234-1235 for 60 minutes at a transfer rate of1,200 bps, such a data train constituted from different function signalsfor a DTMF signal as

    01#060#0990*1234*1235

is sent out in a multiplexed condition with a main broadcasting audiosignal in an interposed relationship between the function signal of "A"and the function signal of "D". Of the data train here, the first "01"represents that the interactive television specification version is 01(transfer rate: 1,200 bps), and the numeric data following the symbol"#" at the second occurrence represents the reception telephone number.

It is to be noted that, in such a data train regarding a response accessas described above, the symbol "#" serves as a separator (for separatingdifferent data from each other), and the symbol "*" represents a pause.

For the response limiting information of the information regardingenvironmental setting, identification information set for eachsubscriber is set. As such identification number of a subscriber, atelephone number of a telephone set connected to a modem is registeredin an SRAM as hereinafter described. In this instance, registration ofan identification number is performed for each receiving apparatus byits subscriber. Where registration of an identification number isperformed by its subscriber in this manner, since the subscriber may notpossibly perform registration of the telephone number, preferably an ID(identification) number which is set upon production of the telephoneset is utilized as in a satellite broadcasting decoder. In other words,upon shipment of a receiving apparatus from a factory, an identificationnumber is registered into an SRAM or a like element of the receivingapparatus.

Then, when it is intended to limit accessing only to those subscribershaving particular identification numbers, for example, when it isintended to permit accessing only to those identification numbers whoselast digit is 0, such a data train constituted from several functionsignals for a DTMF signal as

    0#0

is sent out, but when it is intended to permit accessing only to thoseidentification numbers whose last digit is 1, such a data trainconstituted from several function signals for a DTMF signal as

    0#1

is sent out, in a multiplexed condition with a main broadcasting audiosignal in an interposed relationship between the function signal of "B"and the function signal of "D". In this instance, the numeral "0" priorto the symbol "#" signifies permission of accessing from subscribers ofidentification numbers which has a numeral following the symbol "#" asthe last digit.

On the other hand, when it is intended to permit accessing only to thoseidentification numbers whose last digit is one of even numbers, such adata train constituted from different function signals for a DTMF signalas

    0#0*0#2*0#4*0#6*0#8

is sent out in a multiplexed condition with a main broadcasting audiosignal in an interposed relationship between the function signal of "B"and the function signal of "D". Here, the symbol "*" signifies logicalORing.

Further, as time instant information for use for reservation ofreception or recording of a broadcasting program, for example, when thepresent time instant is 7:00, Dec. 15, Tuesday, 1993, such a data trainconstituted from different function signals for a DTMF signal as

    1#1993121520700

is sent out in a multiplexed condition with a main broadcasting audiosignal in an interposed relationship between the function signal of "B"and the function signal of "D".

On the other hand, for example, when a certain broadcasting program isplanned to be broadcast, as viewed from the present point of time, from7:00 to 7:29 on next Sunday, such a data train constituted fromdifferent function signals for a DTMF signal as

    10#07000729

is sent out in an interposed relationship between the function signal of"B" and the function signal of "D", and then a next broadcasting programis planned to be broadcast from 12:00 to 14:15 on next Monday, such adata train constituted from different function signals for a DTMF signalas

    11#12001415

is sent out in an interposed relationship between the function signal of"B" and the function signal of "D".

It is to be noted that, in such a data train regarding environmentalsetting as described hereinabove, the symbol "#" serves as a separator,and the symbol "*" represents "logical ORing".

Further, as information regarding clearing of reception data, when theinformation represents clearing of a limitation in number, such a datatrain constituted from different function signals for a DTMF signal as

    99#0

is sent out in an interposed relationship between the function signal of"C" and the function signal of "D".

Further, when the information represents clearing of a receptiontelephone number, such a data train constituted from different functionsignals for a DTMF signal as

    99#0

is sent out in an interposed relationship between the function signal of"C" and the function signal of "D".

Where the function signals of "A", "B", "C" and "D" which are not usedfor a selection signal for a telephone line are used for transmissionstarting information and transmission ending information of subbroadcasting information, even if DTMF sound is transmitted, forexample, on a scene on which a telephone call is originated, the DTMFsound will not be confused with information relating to a program.Further, sub broadcasting information can be transmitted and receivedwith certainty.

Subsequently, an embodiment of the present invention wherein a receivingapparatus for a two-way broadcast according to the present invention isapplied to a television receiver designed so as to cope with a two-waybroadcasting program.

The television receiver for a two-way broadcast is schematically shownin FIG. 1. Referring to FIG. 1, the television subscriber shown includesa signal system 10, and a control system 20 for controlling the signalsystem 10. Broadcast radio waves received by an antenna 1 are suppliedto a tuner 11. A channel selection signal is supplied from the controlsystem 20 to the tuner 11, and a broadcasting signal of the desiredchannel is converted into an intermediate frequency signal by the tuner11. The intermediate frequency signal is supplied to an intermediatefrequency circuit 12. The intermediate frequency circuit 12 includes avideo demodulator 13 and an audio demodulator 14, by which a videosignal and an audio signal are demodulated, respectively. The videosignal S13 from the video demodulator 13 is supplied by way of a videosignal processing circuit 15 to a television picture tube 16. The audiosignal S14 from the audio demodulator 14 is supplied to a soundmultiplex decoder 17, by which two-language signals or stereo signals SLand SR are decoded. Then, the signals SL and SR are supplied to a pairof left and right loudspeakers 19L and 19R by way of a pair ofamplifiers 18L and 18R, respectively.

The audio signal S14 from the audio demodulator 14 is supplied to a DTMFdecoder 32 by way of a pre-processing circuit 31. The DTMF decoder 32normally searches for a DTMF signal in an input signal inputted thereto,and when a DTMF signal is detected, the DTMF decoder 32 decodes the DTMFsignal to detect which function signal the DTMF signal is. Inparticular, the DTMF signal is decoded into any of the numerals of "0"to "9" and "#", "*" and "A" to "D". The thus decoded data are suppliedto the control system 20.

In the present embodiment, a DTMF decoder which is widely available onthe market is employed as the DTMF decoder 32. The pre-processingcircuit 31 is provided for performing pre-processing to allow decodingof a DTMF signal with a higher degree of accuracy even if a DTMF decoderon the market is employed as the DTMF decoder 32 in this manner. Inparticular, the pre-processing circuit 31 removes, from the audio signalS14, frequency components other than the DTMF signal so that an inputsignal to the DTMF decoder 32 may be a signal which allows use of a DTMFdecoder on the market, and is constituted from a filter circuit.

Further, in the present embodiment, a modem (modulator-demodulatorapparatus) 33 for data communication is provided in order to cope with atwo-way broadcasting program such as a response to a participation typeprogram. A telephone line 2 is connected to a line connection terminalLine of the modem 33, and a telephone set 3 is connected to a telephoneterminal Tel of the modem 33. The modem 33 is connected to a system bus200 of the control system 20. Meanwhile, data from the modem 33 aresupplied to the DTMF decoder 32, by which a DTMF signal sent thereto byway of the telephone line 2 is decoded so that it can be fetched intothe control system 20.

The control system 20 includes a CPU (central processing unit) 21, a ROM(read only memory) 22, a DRAM (dynamic random access memory) 23, an SRAM(static random access memory) 24 and a video RAM (random access memory)(VRAM) 25, which are individually connected to the system bus 200. TheROM 22 has stored therein a reception fetching processing program forDTMF data, which will be hereinafter described, and various controlprograms as well as font data and graphic data for use for displaying.The DRAM 23 is used as a working area principally for calculation.Setting information, ID information and so forth of the receivingapparatus itself are stored in the SRAM 24. The video RAM 25 is used tostore an image to be displayed.

The control system 20 has I/O ports 261, 262, 263 and 264 and a controlport (VTR control port) 27 for a video tape recorder. A control signalis supplied to the video signal processing circuit 15 and the soundmultiplex decoder 17 via the I/O port 261. Further, for example, aninfrared ray remote control signal from a remote control transmitter 34is received by a remote control receiver 35, and the thus receivedremote control signal is decoded by a remote control decoding circuit(decoder) 36. The decoded remote control signal is fetched into thecontrol system 20 via the I/O port 261. Then, the CPU 21 controls, inresponse to an operation of the remote control transmitter 34 by a user,in accordance with a program of the ROM 22. For example, when theoperation for remote control is for channel selection or volume control,channel selection or volume control of the tuner is performed, and fontdata for use for displaying of necessary characters or symbols are readout from the ROM 22 and transferred to the video RAM 25. Then, the dataof the video RAM 25 are supplied to the video signal processing circuit15, by which they are composed (for example, superimposed) with thevideo signal S13 so that they are displayed on the screen of thetelevision picture tube 16 for a suitable period of time.

Such data for channel selection or volume control are written, uponevery operation, into the non-volatile SRAM 24 so as to realize the lastmemory function by which the same channel can be enjoyed, when the powersource is disconnected once and then connected again, with an equalsound volume to that immediately prior to the disconnection of thepower. A channel selection signal is supplied to the tuner 11 via theI/O port 263. Further, in the present embodiment, a notification of anactual time or time data from a timer circuit 37 for timer interruptionafter a predetermined time are inputted to the control system 20 via theI/O port 264. Meanwhile, the control port 27 for a video tape recorderis constructed so that it can control three video tape recorders VTR1,VTR2 and VTR3. The control system 20 supplies a control signal to avideo tape recorder via the control port 27 and fetches a status signalfrom the video tape recorder to effect desired control of the video taperecorder.

It is to be noted that each of the video tape recorders includes a tunerand an intermediate frequency circuit, which are connected to theantenna 1, for example, by way of a distributor so that they canindividually perform reserved recording under the control of the controlsystem 20 as hereinafter described.

Subsequently, reception processing of multiplexed information of thereceiving apparatus of the embodiment of FIG. 1 will be described withadditional reference to FIGS. 4 and 5. When the power source to thetelevision subscriber is on, a DTMF signal mixed in an audio signal of aprogram of a channel selected at present is normally supervised usingthe pre-processing circuit 31 and the DTMF decoder 32. In particular,the CPU 21 searches the output of the DTMF decoder 32 continuously or ata predetermined interval via the I/O port 262 (step 101), and when it isdetected that a DTMF signal is mixed in the audio signal S14 of thebroadcasting program being received at present (step 102), a decodeoutput D32 of the DTMF signal is fetched as a numeral or a symbol asdescribed hereinabove (step 103).

Then, it is checked to determine whether such sending out conditions asdescribed above are satisfied, that is, whether or not the duration ofthe DTMF signal is longer than 50 msec, whether or not the pause timetill a rising edge of a next signal after the DTMF signal disappears islonger than 30 msec or whether or not the sum of the duration of theDTMF signal and the pause time is longer than 120 msec of prescribedtime to detect whether or not the detected signal really is a DTMFsignal (step 104). Consequently, reception of error data when thereception condition of broadcasting radio waves is bad can be prevented,and erroneous reception can be prevented when same frequency componentsas those of a DTMF signal are unexpectedly included in ordinary sound.

When it is determined at step 104 that the reception data are not a DTMFsignal, the control sequence advances to step 105, at which thetemporary storage area of the DRAM 23 is cleared and a storage pointeris initialized, whereafter, the control sequence returns to step 101 tocontinue the checking of the output of the DTMF decoder 32.

On the contrary when it is determined at step 104 that the receptiondata are a DTMF signal, the control sequence advances to step 106, atwhich it is checked whether or not a storage pointer address is withinthe range of the temporary storage area. Then, when the storage pointeraddress is not within the temporary storage area, since this is acondition immediately after the power source is connected or is an errorcondition, the control sequence advances from step 106 to step 107, atwhich an address of the temporary storage area is initialized into thestorage pointer for resetting. Consequently, such a situation that,while the address indicated by the storage pointer remains indefinite,data are written into the DRAM 23 to cause malfunction or softwarerunaway can be prevented. When it is determined at step 106 that thepointer address is within the temporary storage area, or after theaddress of the temporary storage area is initialized into the pointer atstep 107, the control sequence advances to step 108, at which it isdiscriminated whether the reception data are data of any of the numeralsfrom "0" to "9" or symbol data such as "#" or "*". When the data aredetermined to be a numeral or a symbol, the control sequence advancesfrom step 108 to step 109, at which it is checked whether or not thereis a free area in the temporary storage area.

Then, when the reception data are numeral or symbol data and there is afree area in the temporary storage area, that is, when the pointerindicates an address within the range of the temporary storage area, thecontrol sequence advances to step 110, at which the reception data ("0"to "9", "#" or "*") are stored into the address indicated by thepointer. Thereafter, the control sequence advances to step 111, at whichthe pointer is updated by one character. Thereafter, the controlsequence returns to step 101 to repeat the reception checking of a DTMFsignal.

On the contrary when it is determined at step 109 that there is no freearea in the temporary storage area, since this signifies a receptionerror, the control sequence advances to step 112, at which the temporarystorage area is cleared and the address of the temporary storage area isinitialized into the pointer.

On the other hand, when it is determined at step 108 that the receptiondata are not such numeric or symbol data as "0" to "9", "#" or "*",since the reception data are one of the character data "A", "B", "C" and"D" corresponding to the four function signals described above, thecontrol sequence enters a routine 120 for classification storage of FIG.4. The routine 120 has such contents as illustrated in FIG. 5. Referringnow to FIG. 5, the top address of the temporary storage area is placedinto the pointer at step 121. Then at steps 122, 123 and 124, thereception data are successively checked to determine which one of thethree function signals of "A", "B" and "C" the reception data represent.

Then, when it is determined at step 122 that the reception datarepresent the function signal of "A", the control sequence advances tostep 125, at which "A" is placed into the address designated by thepointer. On the other hand, when it is determined at step 123 that thereception data represent the function signal of "B", the controlsequence advances to step 126, at which "B" is placed into the addressdesignated by the pointer. Further, when it is determined at step 124that the reception data represent the function signal of "C", thecontrol sequence advances to step 127, at which "C" is placed into theaddress designated by the pointer.

Then, subsequently to step 125,126 or 127, the control sequence advancesto step 111, at which the pointer is updated by one character.Thereafter, the control sequence returns to step 101, at which thereception checking of a DTMF signal is continued.

When it is determined at steps 122 to 124 described above that thereception data are not any one of the three functions of "A", "B" and"C", it is determined that the reception data are the function signal ofthe remaining character "D", and the data stored into the temporarystorage area before then are processed as a single data train(information set).

In particular, since the broadcasting side sends out, upon transmissionof a DTMF signal, one of the function signals of "A", "B" and "C" as atransmission starting signal, as a result of the processing at steps 125to 127, one of "A", "B" and "C" is stored at the top of the temporarystorage area. Thus, at next step 128. it is determined which one of thecharacter data of "A", "B" and "C" the top of the temporary storage areais. If the result of determination reveals that the top of the temporarystorage area is "A", then the control sequence advances to step 129, atwhich the data train from the top of the temporary storage area to thelast portion indicated by the pointer is stored into a correspondingstorage area Ga. On the other hand, if the top of the temporary storagearea is "B", the control sequence advances to step 130, at which thedata train from the top of the temporary storage area to the lastportion indicated by the pointer is stored into a corresponding storagearea Gb. Further, if the top of the temporary storage area is "C", thenthe control sequence advances to step 131, at which the data train fromthe top of the temporary storage area to the last portion indicated bythe pointer is stored into a corresponding storage area Gc. The storageareas Ga, Gb and Gc are set in the DRAM 23 or the SRAM 24 as hereinafterdescribed.

Subsequently, the control sequence advances to step 132, at whichevaluation and analysis of the received data train are performed, andwhen the information stored in the storage area Ga, Gb or Gc is acommand which must be executed upon reception, processing correspondingto the command such as, for example, clearing of part or all of thereceived information, setting of the present time instant into the timeror menu display selection processing, is performed. Thereafter, thecontrol sequence returns to step 101, at which the reception checking isrepeated.

As described above, in the reception processing of multiplexed data bythe receiving apparatus of the present embodiment, an audio signal of abroadcasting program is supervised continuously, and a data traininterposed between the function signals of the character data "A" and"D", "B" and "D" or "C" and "D" corresponding to the function signalsfor a DTMF signal is regarded as a set of information and classified inaccordance with the kind of information as described above. Thus, theinformation is automatically stored into the individual correspondingstorage area Ga, Gb or Gc. In this manner, in the receiving apparatus ofthe present embodiment, reception information can be stored in aclassified condition.

For example, when the start of the data train is the function signal of"A", the data train is stored into the storage area Ga as informationwhich relates to a response access to the two-way program; when thestart is the function signal of "B", the data train is stored into thestorage area Gb as information relating to environmental setting; butwhen the start is the function signal of "C", then the data train isstored into the storage area Gc as information regarding clearing ofreception data.

While temporary information corresponding to a two-way program such asinformation regarding a response access may be cleared upon reception ofa program clearing signal, if the possibility that the channel may havebeen changed before reception of the clearing signal is taken intoconsideration, an old number is preferably cleared at a timing at whichthe power source is disconnected. Accordingly, information regarding aresponse access may be stored as it is into the DRAM 23. Or in otherwords, the storage area may be set on the DRAM 23.

On the other hand, information regarding environmental setting includestime instant information for reception reservation or recordingreservation of a broadcasting program, and the time instant informationof the reserved program must be kept reserved for a comparatively longperiod of time which may exceed, for example, one week. Therefore, suchinformation should be transferred to the non-volatile SRAM 24.Accordingly, in the receiving apparatus of the present embodiment, thestorage area Ga, Gb or Gc is set to the volatile DRAM 23 or thenon-volatile SRAM 24 depending upon a nature of data to be stored, thatis, the condition of whether or not storage for a long period of time isrequired or whether or not the data may be erased upon disconnection.

Then, upon such response processing of a simplified interactivetelevision system wherein a universal telephone line is utilized fortransmission of information in an ascending direction to the centeroffice as described hereinbelow, information necessary for a destinationtelephone number or communication conditions stored in the storage areaGa of the DRAM 23 can be automatically read out and utilized.

On the other hand, also upon such recording reservation as describedhereinbelow, time instant information of a reserved program transferredfrom the storage area Gb of the DRAM 23 to the SRAM 24 can be utilizedautomatically.

Subsequently, response processing of the receiving apparatus of thefirst embodiment of FIG. 1 will be described with reference to FIG. 6.

When a subscriber operates the remote control transmitter 34 at step141, a remote control signal transmitted from the remote controltransmission 34 is received by the remote control receiver 35. Then, itis determined at step 142 whether or not the thus received command is aresponding command for responding to a program of a two-way broadcastsuch as, for example, a quiz program of the participation type. When thereceived command is a universal command such as, for example, changingof a channel, processing corresponding to the command is executed atstep 140.

On the other hand, when the received command is a responding command, itis determined at step 143 whether or not access information such as atelephone number of a reply destination and a communication rate hasbeen received and stored into the DRAM 23 as a result of such receptionprocessing as illustrated in FIGS. 4 and 5, and if no access informationhas been received, it is displayed, at step 144, on the screen of thetelevision picture tube 16 for a fixed period of time by way of an iconor message representing an error that no access information has beenreceived.

On the other hand, if reply destination information has been receivedalready at step 143, then it is determined at steps 145 and 146 whetheror not there is transmission limiting information receivedsimultaneously and whether or not the subscriber satisfies the limitingcondition.

The limiting condition here is set, on the broadcasting station side, byway of such information regarding environmental setting as describedhereinabove and limits origination of a telephone call, for example, bydesignating the last digit of the identification numbers of thesubscribers each stored in the SRAM 24 of each receiving apparatus. Forexample, when it is intended to limit responses so as to permitaccessing only to those of subscribers having identification numberswhose last digit is, for example, "0", accessing is permitted to thosesubscribers having identification numbers which have the last digit of"0" while those subscribers having identification numbers havingdifferent last digits are inhibited from originating a telephone call.When the subscriber satisfies such limiting condition and is inhibitedfrom originating a telephone call, a message representing this isdisplayed for a fixed time on the television picture tube 16 at step147. Then, when there is no limiting condition or when the subscriberdoes not satisfy the limiting condition, the identification number ofthe subscriber is added, at step 151, to the information as a responseto the broadcasting program to produce response information, and acommunication rate is set in accordance with such response destinationinformation as described above, whereafter the response information istransmitted by way of the modem 33 toward the predetermined telephonenumber stored in the DRAM 23.

At subsequent step 152, it is determined whether or not the responseinformation has been transmitted successfully, and if the responseinformation has been transmitted successfully, then the telephone lineis disconnected at step 153, displaying the message "transmission hasbeen performed" on the screen for certain period at step 154. But iftransmission of the response information has failed, a messagerepresenting this is displayed on the screen for a fixed period of timeat step 155.

It is to be noted that the condition of limiting origination of atelephone call at step 146 may be such that accessing is limited to onlyone of a plurality of subscribers participating in the program byselecting a particular one ID number. In this instance, suitable datarepresenting participation in the program are transmitted from thesubscribers to the broadcasting station side in advance.

Further, by combining the limiting condition just described with suchtime limit of information regarding a response access as describedhereinabove, it is possible to inhibit accessing only for a fixed periodof time and then permit accessing.

By limiting the last digit in this manner, the broadcasting side canperform two-way broadcasting readily while it controls the amount ofresponses from the subscriber side.

In the meantime, on the subscriber side, even if an ineffectiveresponding operation is performed in error while accessing is limited, atelephone call is not originated, and accordingly, no useless load isapplied to a telephone line and no useless rental fee for the telephoneline is required. Further, the subscriber side can respond readily andwith certainty by automatically utilizing access information reproducedfrom a reception signal.

Further, as response information, an ID number peculiar to an individualsubscriber such as SONY-01-23456789 is added to such an answer as "#1",for example, to a question in a quiz program of the participation type.

Consequently, the broadcasting side can recognize from a subscriber ofwhich maker it is accessed, and the information can be utilized as fixedroyalty payment information for the fee for a telephone call.

Since, in the present embodiment, information relating to a program isbroadcast in the form of a DTMF signal in a multiplexed condition withan audio signal of a program as described above, such an inexpensivecircuit as a DTMF subscriber chip, which is formed as a DTMF decoderinto an IC and produced in a mass, can be used on the reception side.Consequently, a more inexpensive subscriber than a subscriber which canreceive a character multiplex broadcast can be provided.

Further, as distinct from transmission in the form of a charactermultiplex broadcast, the receiving apparatus can receive various typesof broadcasts by means of a same circuit and no influence is had on theconventional broadcasting systems.

Indeed, the transfer rate of information in the receiving apparatus ofthe present embodiment is approximately 8 characters/second as apparentfrom the period of a DTMF signal described above and is very low ascompared with the transfer rate of information by the charactermultiplex system. However, since the required information amount issmall as described above, the transfer rate need not be placed inquestion.

Since the present time instant or such time instant information as thetime instant regarding reception reservation or recording reservation ofa broadcasting program can be broadcast as multiplex broadcast in theform of a DTMF signal as a data train wherein the function signals of"B" and "D" are included as transmission starting information andtransmission ending information, respectively, amendment to the timeinstant of a timer or simplification in operation for reservation of aprogram can be achieved by making use of the time instant information.

Where, for example, accurate information of the present time instant istransmitted as the time instant information, correction or setting ofthe present time instant of, for example, the timer circuit 37 or atimer as a time circuit possessed by a video tape recorder itself can beperformed readily making use of the accurate time instant information.In particular, when the present time instant information is received,the time count of, for example, the timer circuit 37 may be setautomatically to the thus received present time instant.

Further, on the broadcasting station side, simultaneously withannouncement broadcasting of a certain program, broadcasting timeinformation of the program is broadcast in the form of a DTMF signal bymultiplex broadcast, and on the reception side, when the announcementbroadcasting and the broadcasting time information are received, if areservation button of the remote control transmitter 34 is depressedwithin a predetermined time, data of a broadcasting starting timeinstant and a broadcasting ending time instant of the announcementprogram are automatically stored into the area Gb of the DRAM 23. Then,in the receiving apparatus, the data of the broadcasting starting timeinstant and the broadcasting ending time instant of the announcementprogram are transferred to the SRAM 24 and used as recording reservationdata.

In this instance, selection channel data of a channel enjoyed then iswritten into the SRAM 24 so that it is used also as recordingreservation data.

Then, when the broadcasting starting time instant of the announcementprogram comes, a video tape recorder connected to the receivingapparatus via the control port 27 is started by interruption from thetimer circuit 37 so that recording is started. Then, when thebroadcasting ending time instant of the reserved program comes, thevideo tape recorder stops its operation by interruption from the timercircuit 37 again, thereby ending the reserved recording.

It is to be noted that, in the case of a program reservation, atelevision subscriber itself starts and stops its operation similarly asdescribed above.

It is to be noted that, while, in the embodiment described above, one ofthe function signals of "A", "B" and "C" is used as transmissionstarting information of sub broadcasting information and the functionsignal of "D" is used as transmission ending information of the subbroadcasting information, any one of the function signals of "A", "B","C" and "D" may be arbitrarily used as transmission starting signal ortransmission ending signal.

Meanwhile, if a predetermined one of the function signals such as, forexample, the function signal of "D" is used as transmission endinginformation and a combination of a plurality of ones of the otherfunction signals of "A", "B" and "C" (an overlap is permitted and adifference in order is taken into consideration) is used as transmissionstarting information, then the number of classifiable kinds of subbroadcasting information can be increased. Further, also thetransmission ending signal may be one of combinations of a plurality ofdifferent function signals permitting an overlap and taking a differencein order into consideration.

Further, the transmission starting information and the transmissionending information may each be a particular combination of "0" to "9","#" and "*". Or each of them may be a combination selected from thenumerals and the symbols as well as "A" to "D".

It is to be noted that, while, in the embodiment described above, a mainaudio signal is broadcast with origination limiting information in theform of a DTMF signal multiplexed therewith, similar effects to those ofthe embodiment described above can be achieved also by broadcasting theorigination limiting information in a multiplexed condition with a videosignal in character multiplex broadcasting.

Further, while, in the embodiment described above, the present inventionis applied to television broadcasting and a television subscriber, sincethe present invention resides in that sub broadcasting information suchas accessing data or program reservation data of a two-way broadcast isconstructed using, for example, a DTMF signal within a comparativelynarrow audio band and is broadcast in a multiplexed condition with amain broadcasting audio signal, the present invention can be appliedalso to AM or FM radio broadcasting and a receiving apparatus for suchbroadcasting.

Subsequently, a second embodiment of the present invention wherein areceiving apparatus for a two-way television broadcast to which atwo-way broadcasting method according to the present invention isapplied is applied to a television receiver designed so as to cope witha two-way broadcasting program. In particular, in the presentembodiment, the broadcasting station side broadcasts, upon broadcastingof a two-way program, information relating to the two-way programincluding information of a reply destination or a response limit time assub broadcasting information in a multiplexed condition with a mainbroadcasting television signal. On the other hand, the receiver sidedemultiplexes and reproduces the information relating to a two-wayprogram from a received video signal, stores the information into amemory and utilizes the information for a response to the two-waybroadcasting program. In the present embodiment, information relating toa two-way program is multiplexed, in the form of a signal in an audioband such as a DTMF (Dual Tone Multi-Frequency) signal which can bedistinguished readily from main broadcasting sound, with a mainbroadcasting audio signal similarly as in the first embodiment describedhereinabove.

In particular, the broadcasting station side constructs informationrelating to a program as sub broadcasting information into a signal ofthe DTMF signal form, multiplexes (mixes) the signal with a mainbroadcasting audio signal and broadcasts the multiplexed signal. On theother hand, the receiver side demultiplexes the DTMF signal from thereceived broadcasting audio signal, decodes the DTMF signal to reproduceinformation relating to a program, stores the information into a memoryand utilizes the information upon transmission of response informationto a reply destination.

Since the DTMF signal is described in detail hereinabove in connectionwith the first embodiment of the present invention, overlappingdescription thereof is omitted herein.

Broadcasting of Sub Broadcasting Information

Also broadcasting of sub broadcasting information is performed in asimilar manner as in the first embodiment described hereinabove. Inparticular, on the transmission side, that is, on the broadcastingstation side, among the function signals signifying "A", "B", "C" and"D" which are not used for selection of a PB telephone line, thefunction signals of "A", "B" and "C" are used for transmission startinginformation for sub broadcasting information while the function signalof "D" is used for transmission ending information upon transmission ofsub broadcasting information. Since three different kinds oftransmission starting information are provided, three different kinds ofsub broadcasting information can be transmitted distinctly. Inparticular, each of the three kinds of sub broadcasting information isdelineated, when broadcast, by one of the function signals of "A", "B"and "C" and the function signal "D".

For example, information regarding a response access to a two-wayprogram, for example, sub broadcasting information such as a telephonenumber (reception telephone number) of a reply access destination and atransfer rate, is transmitted between the function signal of "A" astransmission starting information and the function signal of "D" astransmission ending information. Further, for example, sub broadcastinginformation regarding environmental setting such as response limitinginformation for the responding side and setting of the present timeinstant is broadcast in a multiplexed condition as a signal interposedbetween the function signal of "B" and the function signal of "D", andinformation regarding clearing of reception data is broadcast in amultiplexed condition as a signal interposed between the function signalof "C" and the function signal of "D".

Then, on the receiver side, numerical and/or symbol data interposedbetween one of the function signals "A", "B" and "C" as transmissionstarting information and the function signal of "D" as broadcastingending information are regarded as a sub broadcasting data train(information set) and are stored distinctly into a predetermineddifferent storage area of a memory as hereinafter described.

For example, when accessing for 120 minutes at the transfer rate of 300bps to a reception telephone number of 0990-1234-1234 as a replydestination of a response is to be permitted to telephone receiverswhose interactive television specification version is 00, as informationregarding a response access to shopping by way of television, subbroadcasting information of such a data train constituted from differentfunction signals for a DTMF signal as

    00#120#0990*1234*1234

is transmitted in a multiplexed condition with a main broadcasting audiosignal in an interposed relationship between the function signal of "A"and the function signal of "D". Of the data train here, the first "00"represents that the interactive television specification version is 00(transfer rate: 300 bps), and the numeric data following the symbol "#"at the second occurrence represents the reception telephone number.

On the other hand, when it is tried to permit receivers whoseinteractive television specification version is 01 to access to atelephone number 0990-1234-1235 for 1 minute at a transfer rate of 1,200bps as information regarding a response access to a quiz program of thefast depression type, such a data train constituted from differentfunction signals for a DTMF signal as

    01 #001#0990*1234*1235

is sent out in a multiplexed condition with a main broadcasting audiosignal in an interposed relationship between the function signal of "A"and the function signal of "D". Of the data train here, the first "01"represents that the interactive television specification version is 01(transfer rate: 1,200 bps), and the numeric data following the symbol"#" at the second occurrence represents the reception telephone number.

It is to be noted that, in such a data train regarding a response accessas described above, the symbol "#" serves as a separator (for separatingdifferent data from each other), and the symbol "*" represents a pause.

When it is intended to limit accessing only to those receivers havingparticular telephone numbers (subscriber numbers), for example, when itis intended to permit accessing only to those telephone numbers whoselast digit is 0, such a data train constituted from several functionsignals for a DTMF signal as

    0#0

is sent out, but when it is intended to permit accessing only to thosetelephone numbers whose last digit is 1, such a data train constitutedfrom several function signals for a DTMF signal as

    0#1

is sent out, in a multiplexed condition with a main broadcasting audiosignal in an interposed relationship between the function signal of "B"and the function signal of "D". In this instance, the numeral "0" priorto the symbol "#" signifies permission of accessing from receivers oftelephone numbers which have a digit following the symbol "#" as thelast digit. On the other hand, when it is intended to permit accessingonly to those telephone numbers whose last digit is one of even numbers,such a data train constituted from different function signals for a DTMFsignal as

    0#0*0#2*0#4*0#6*0#8

is sent out in a multiplexed condition with a main broadcasting audiosignal in an interposed relationship between the function signal of "B"and the function signal of "D". Here, the symbol "*" signifies logicalORing.

Further, as time instant information for reservation of reception orrecording of a broadcasting program, for example, when the present timeinstant is 7:00, Dec. 15, Tuesday, 1993, such a data train constitutedfrom different function signals for a DTMF signal as

    1#1993121520700

is sent out in a multiplexed condition with a main broadcasting audiosignal in an interposed relationship between the function signal of "B"and the function signal of "D".

On the other hand, when a certain broadcasting program is planned to bebroadcast, as viewed from the present point of time, from 7:00 to 7:29on next Sunday, such a data train constituted from different functionsignals for a DTMF signal as

    10#07000729

is sent out in an interposed relationship between the function signal of"B" and the function signal of "D", and then a next broadcasting programis planned to be broadcast from 12:00 to 14:15 on next Monday, such adata train constituted from different function signals for a DTMF signalas

    11#12001415

is sent out in an interposed relationship between the function signal of"B" and the function signal of "D".

It is to be noted that, in such a data train regarding environmentalsetting as described hereinabove, the symbol "#" serves as a separator,and the symbol "*" represents "logical ORing".

Further, as information regarding clearing of reception data, when theinformation is for clearing of a limitation in number, such a data trainconstituted from different function signals for a DTMF signal as

    99#0

is sent out in an interposed relationship between the function signal of"C" and the function signal of "D".

Where the function signals of "A", "B", "C" and "D" which are not usedfor a selection signal for a telephone line are used for transmissionstarting information and transmission ending information of subbroadcasting information, even if DTMF sound is transmitted, forexample, on a scene on which a telephone call is originated, the DTMFsound will not be confused with information relating to a program.Further, sub broadcasting information can be transmitted and receivedwith certainty.

FIG. 7 shows a receiving apparatus for a two-way broadcast according tothe second preferred embodiment of the present invention. Referring toFIG. 7, the receiving apparatus shown is a modification to the receivingapparatus of the first embodiment described hereinabove with referenceto FIG. 1, and overlapping description of common components is omittedherein to avoid redundancy.

The receiving apparatus has identification information of itself. Suchidentification information is an identification number peculiar to anindividual apparatus set upon production of a television receiver whichis designed to cope with a two-way broadcasting program, such as, forexample, "SONY-00-00000001". A user will register, after purchase of atelevision receiver designed to cope with a two-way broadcastingprogram, the identification information of the television receiver andthe name, the address, the telephone number and so forth of the userinto a data base of a data base center which is a reply destination of aresponse of a receiver of a two-way television program. In the data basecenter, the individual information corresponding to the identificationinformation of the television receiver is controlled on the data base.By including the identification information of the receiving apparatusinto information of a response to a two-way program, it can be readilyidentified by the data base center of the reply destination from which aresponse has been received.

The television receiver of the present embodiment is different from thetelevision receiver of the first embodiment only in that the video RAM25 includes a display controller 25C. The display controller 25Ccontrols reading and writing of video data from and into the video RAM25 and converts video data read out from the video RAM 25 into an analogvideo signal. The analog video signal thus obtained from the displaycontroller 25C is supplied to the video signal processing section 15, bywhich it is superimposed or switchably composed with a video signal fromthe intermediate frequency circuit 12 under the control of the videosignal processing section 15 from the control section 20.

Further, the control system 20 uses time instant information from thetimer circuit 37 to recognize a time instant (responding operation timeinstant) at which a responding operation is performed and calculate atransmission time instant as hereinafter described.

Subsequently, dispersion processing for a response transmission timeinstant of the television receiver of FIG. 7 will be described withreference to FIGS. 8 and 9. FIG. 8 illustrates processing executedprincipally by the control section 20 of the two-way broadcast receivingapparatus for dispersing the transmission time instant of responseinformation, and FIG. 9 illustrates the relationship between a timeinstant and transmission of response information.

In the present embodiment, a data train which represents a telephonenumber of a reply destination, a response permission time and so forthand may include the numerals "0" to "9" and the symbols "*" and "#" ismultiplexed (mixed) in the form of a DTMF signal described above with amain broadcasting audio signal and transmitted in the multiplexedcondition from the broadcasting station side. In the present embodiment,the response permission time is set as a relative time from the presenttime instant.

A broadcasting signal in which such DTMF signal is multiplexed isreceived and selected by the tuner 11. Then, a video signal and an audiosignal of the receiver broadcasting signal are demodulated by the videodemodulator 13 and the audio demodulator 14 of the intermediatefrequency circuit 12. Then, the DTMF signal is extracted from the audiosignal from the audio demodulator 14 and decoded into data of a numeralor numerals and a symbol or symbols by the pre-processing circuit 31 andthe DTMF decoder 32, respectively, and then fetched into, for example,the DRAM 23 of the control system 20 via the I/O port 262. Then, thetelephone number of the reply destination is transferred to and writteninto and thereafter held in the SRAM 24. Further, a response permissionending time instant is calculated from the response permission time setas a relative time and the present time instant provided from the timercircuit 37 and is written into and thereafter held in the SRAM 24.

The storage of the information regarding the reply destination into theSRAM 24 is performed prior to requesting for a response provided by thebroadcasting program, for example, when the broadcasting program is aquiz program, prior to making a question. In other words, writing of thetelephone number of the reply destination, the response permission timeand the response permission ending time instant into the SRAM 24 iscompleted prior to making a question of a quiz.

Then, after a question of a quiz is made, for example, in a broadcastingprogram, a subscriber will operate the remote control transmitter 34 toperform a responding operation such as selection. Thus, the controlsystem detects that a responding operation has been performed, detects atime instant of the responding operation from time instant informationfrom the timer circuit 37 and writes the time instant of the respondingoperation into the DRAM 23. Then, the control system 20 of the receivingapparatus executes processing for dispersing the transmission time ofresponse information so that transmission of response information maynot be performed in a concentrated condition.

In the present embodiment, the processing of dispersing transmissions ofresponses which occur in a concentrated manner immediately after thestarting time instant of response permission and responses which occurin a concentrated manner immediately before the ending time instant E ofresponse permission is executed in the following manner.

In the present embodiment, it is assumed that, as seen in FIG. 9,concentrated responses immediately before the response permission endingtime instant E occur within a time of, for example, approximately 10seconds prior to the response permission ending time instant.Consequently, in the present embodiment, transmissions of responses fromthe time instant P 10 seconds prior to the response permission endingtime instant E to the response permission ending time instant E aredispersed over a predetermined period of time after the responsepermission ending time instant E, in the present embodiment, till thetime instant 0 after 50 seconds. Then, responses occurring after theresponse permission starting time instant before the time instant P aredispersed between the responding operation time instant G and the timeinstant P.

The processing routine for dispersing transmissions of responseinformation is illustrated in FIG. 8. Referring to FIG. 8, the presentroutine is executed as the CPU 21 reads out a processing program of theROM 22 when a responding operation is performed by a user as describedabove.

First, prior to making a question of a quiz, a response permissionending time instant calculated from a response permission time providedas a DTMF signal is read out, and it is determined at step 201 whetheror not the time instant (responding operation time instant) at which theresponding operation is performed exceeds the response permission endingtime instant.

When it is determined at step 201 that the responding operation timeinstant exceeds the response permission ending time instant, sincetransmission of response information to the reply destination side ismeaningless, such an error message as, for example, "The responsepermission time has elapsed." is displayed on the television picturetube 16 or sound is outputted from the loudspeakers 19L and 19R to givea warning to a user that the responding operation is meaningless at step209. Then, the routine is ended without performing transmission ofresponse information.

On the contrary if it is determined at step 201 that the respondingoperation time instant does not exceed the response permission endingtime instant, the identification information of the receiving apparatusheld in the ROM 22 is read out (step 202). The identificationinformation of the receiving apparatus in the present embodiment is, asdescribed hereinabove, an identification number peculiar to theindividual apparatus set upon production of the television receiverdesigned to cope with a two-way broadcasting program. Thereafter, thecontrol sequence advances from step 202 to step 203, at which thepresent time instant G of the timer circuit 37 when the respondingoperation is performed with the remote control transmitter 34 by thesubscriber is fetched as a responding operation time instant, and thetime interval A from the responding operation time instant G to thepoint P 10 seconds prior to the response permission ending time instantE (refer to FIG. 9) is calculated in accordance with the followingexpression for calculation:

    A=(response permission ending time instant E)-(present time instant G+10 seconds)

It is to be noted that the unit of the time interval A is second.

Then at next step 204, it is determined that the time interval Acalculated at step 203 is in the positive or negative in sign. In otherwords, at this step 204, it is determined whether the respondingoperation time instant is between the time instant S and the timeinstant P (A 0) or between the time instant P to the response permissionending time instant E (A<0).

When it is determined at step 204 that the time interval A is not in thenegative in sign, since the time instant at which the respondingoperation is performed by the subscriber is the responding operationtime instant G before the time instant P, the transmission time instantB is set at step 205 using the identification number of the receivingapparatus so that transmission of a response may be executed in adispersed condition at the time A after the responding operation timeinstant G before the time instant P.

The expression for calculation of the transmission time instant B atstep 205 is, for example, ##EQU1## The reason why the time interval A isdivided by 100 in the expression (1) above is that, in the presentembodiment, only the two lowest digits of identification information areused to disperse the transmission time instant of a response in units ofa second within the range of the time interval A.

Since the identification number of the receiving apparatus is a peculiaridentification number and a random number, also the transmission timeinstant B is random, and transmission of response information isdispersed within the time interval A. On the other hand, when it isdetermined at step 204 that the time interval A is in the negative insign, it is determined that the responding operation time instant is theresponding operation time instant g within the range of 10 secondsbetween the time instant P and the response permission ending timeinstant E, and the transmission time instant B is set at step 208 sothat transmission of response information is executed in a dispersedcondition within a period from the responding operation time instant gto the response transmission ending time instant O.

The expression for calculation at step 208 is, for example,

    transmission time instant B=(lower two digits of identification number)×(60/100) +responding operation time instant g(2)

In the expression (2) for calculation above, (60/100) is a division ofthe time interval C (60 seconds) from the time instant P to the timeinstant O by 100 by a similar reason to that described hereinabove inconnection with the expression (1).

After the transmission time instant B is calculated by the processing atstep 205 or 208, transmission of a response is suspended, at step 206,until the present time instant provided from the timer circuit 37 comesto the transmission time instant B. Then, when the present time instantcomes to the transmission time instant B at step 206, transmission of aresponse is executed at step 207. Thereafter, the routine comes to anend.

An example of a format of response information (reply data) transmittedto the reply destination by way of the modem 33 and a telephone line asa result of the transmission of response information is shown in FIG.10.

Referring to FIG. 10, the reply data identification information at thetop of the response information is an identifier for identification ofwhether data received by the broadcasting station side are reply data ordata obtained by some other access.

The subsequent check data include information of a data length andconsistency check data. The data length indicates a length of dataincluding reply data and reply source identification information whichwill be hereinafter described. The consistency check data are data forchecking a check sum of such reply data and reply source identificationinformation or the like. The check data are used to check consistencywhether or not data have been varied by a drop of a bit or bits or bynoise upon transmission of the reply information. The following replydata includes selection procedure identification information andselection result information. The selection procedure identificationinformation of the reply data is selection procedure identificationinformation in sub broadcasting information multiplexed in abroadcasting signal received by the television receiver of FIG. 7. Asdescribed hereinabove, it is determined based on the selection procedureidentification information to which question of which menu the answerfrom the subscriber is. Even if a question 1, another question 2, . . .are broadcast in this order from the broadcasting station, dependingupon the situations of telephone lines, answers from a subscriber maynot necessarily be returned in the same order. Therefore, suchidentification information as described above is required.

Further, as the selection result information, information indicative ofa finally selected menu item, the time instant (responding operationtime instant) at which such selection operation is performed and soforth are returned. The time instant of the timer circuit 37 is used asthe information of the time instant in this instance.

It is to be noted that the responding operation time instant need not bea responding operation time instant itself but may be a differencebetween the transmission time instant and the responding operation timeinstant. In this instance, since information of the response is receivedby the reply destination substantially at the transmission time instant,the responding operation time instant can be recognized as a timeinstant prior by the time of the difference to the time instant of thereception by the reply destination.

Or, in order to identify a responding operation time point, for example,in a quiz program of the "first come, first served" type, a numeral from"0" to "9" or a symbol of a DTMF signal may be broadcast at a fixedinterval in a multiplexed condition with sound similarly as describedabove whereas the numeral or symbol as a DTMF signal receivedimmediately after a responding operation time point by a receivingapparatus side is replied as information regarding the respondingoperation time point of reply data.

The subscriber input data in the selection result information isprovided taking it into consideration that, in some broadcastingprograms, a selection procedure may possibly urge subscribers to performan inputting operation. Further, the subscriber input data may possiblybe, for example, a number of a credit cart or a telephone number of asubscriber replying to shopping by way of television.

For the reply source identification information next to the reply data,a number peculiar to a subscriber, for example, a telephone number ofthe subscriber or an identification number which is a product number ofa receiving apparatus may be used. Subsequently to the reply sourceidentification information, a reply data end code representative of anend of the reply data is sent.

Even if such point of time at which a subscriber performs its respondingoperation using the remote control transmitter 34 in such a manner asdescribed above is concentrated among a large number of subscribers whoenjoy the same two-way television program, the transmission timeinstants of actual responses can be dispersed. Consequently,transmissions of response information which otherwise occur in atemporarily concentrated condition upon a particular telephone line orlines can be dispersed, and an overcrowded condition of telephone linescan be prevented.

Further, since response information transmitted from the reception side(subscriber side) includes information regarding a responding operationtime point, even if the time instant at which transmission of aresponding operation actually takes place passes the response permissionending time instant, it can be determined by the reply destination sidethat the response has been transmitted before the response permissionending time instant. Further, since the point of time at which aresponding operation is performed actually can be identified by thereply destination side irrespective of the point of time at whichresponse information arrives at the reply destination, the two-waybroadcasting method and the two-way broadcast receiving apparatus can beused for a quiz program of the "first come, first served" type.

It is to be noted that, while the two lowest digits of identificationinformation are used in the embodiment described above, finer dispersionin time can be achieved by increasing the number of digits to be used.Meanwhile, transmissions of response information can be dispersed forindividual districts by using an office number of a telephone number ora zip code. Further, while the time from the time instant P to theresponse permission ending time instant E is 10 seconds and the timefrom the time instant P to the response transmission ending time instantO is 60 seconds in the embodiment described above, the numerical valuesare exemplary values at all and can be set arbitrarily. Furthermore,either time information can be varied suitably by setting it by way ofmultiplexed information of a main broadcasting signal or by operatingthe remote control transmitter 34 by a subscriber to set a time input.

While, in the embodiment described above, information relating to aprogram such as reply destination information for responding to atwo-way broadcasting program is constructed using a DTMF signal andforecast in a multiplexed condition with a main broadcasting audiosignal, the information relating to a program may otherwise bemultiplexed in an empty horizontal section within a vertical blankingperiod of a television broadcast similarly as in character multiplexbroadcasting.

In this instance, on the broadcasting station side, such informationrelating to a program as illustrated in FIG. 11 is constructed in theform of a character multiplex signal and broadcast in a multiplexedcondition within a vertical interval of a video signal. Meanwhile, onthe receiving apparatus side, a character multiplex decoder is employedin place of the pre-processing circuit 31 and the DTMF decoder 32 inFIG. 7, and the output signal S13 of the video demodulation circuit 13is supplied to the decoder. The decoded output of the decoder is fetchedinto and decoded by the control system 20 to reproduce the informationrelating to a program, and the information relating a program is storedinto a memory such as a DRAM. Further, such reply information asillustrated in FIG. 10 is produced in response to the receivedinformation relating to a program and transmitted by way of a telephoneline. Thus, on the broadcasting station side, selection procedureinformation, for example, for several questions of a quiz program isfirst produced to make preparations for broadcasting of the program. Ifthe questions are of the type wherein one is selected from within threechoices, a selection procedure wherein three choices are displayed in amenu so that one of them may be selected by a subscriber.

In the case of a quiz program, the reply destination is the receptionsystem of the broadcasting station side, and a communication protocol tothe system and a telephone number for reception are set as replydestination information.

Then, since a point of time when subscribers are requested to make ananswer during broadcasting of, for example, a quiz program, timeinformation, the selection procedure information and the replydestination information are broadcast in a multiplexed condition in avertical interval of a video signal as described below.

FIG. 11 illustrates a manner of multiplexing and contents of informationrelating to a program. Referring to FIG. 11, information relating to aprogram is superimposed, for example, in the case of an NTSC televisionsignal, with one to several horizontal intervals within the 14th H (Hdenotes horizontal interval) (or the 277th H) to the 16th (279th) H andthe 21st (284th) H.

The information relating to a program illustrated in FIG. 7 makes a unitincluding time information, selection procedure information and replydestination information. While a unit of information relating to aprogram is illustrated in an all multiplexed condition within a blankingperiod of image data for one field in FIG. 7, the other information ofthe unit of information relating to a program other than the timeinformation may be multiplexed in a plurality of fields.

Time information is time data updated, in the present modification, foreach one field. Accordingly, the time information is informationpeculiar to each one field as different from selection procedureinformation or reply destination information which may span over aplurality of fields, and has the accuracy of 1/60 second in the case ofan NTSC television signal. The time instant data includes the year,month and day as well as a day of the week. Naturally, the year, monthand day as well as a day of the week need not be included depending uponan application.

It is to be noted that selection procedure information and replydestination information may be omitted so that only time information maybe broadcast as sub broadcasting information in a multiplexed conditionfor each field. Further, time information need not normally bemultiplexed but may be broadcast in a multiplexed condition only for aperiod for which responses of subscribers are anticipated, for example,only upon broadcasting of a two-way program. Further, time informationneed not be updated for each one field but may be updated for eachplurality of fields taking an allowable time instant accuracy intoconsideration.

Selection procedure information is a set of programs like acommunication protocol and includes, in the present modification,selection procedure identification information, information of aselection procedure, display/audio data, time limit information andother information. Since the selection procedure information maypossibly include a considerably great mount of information, it may bemultiplexed over a plurality of fields as described hereinabove.

The selection procedure identification information is an identifierwhich is added to reply information when a subscriber tries to return aresult of selection and is used to allow the reply destination todiscriminate to which selection procedure, that is, to which question,to which questionnaire or to which quiz question the result of selectionis an answer. Reply of the selection procedure identificationinformation allows the reply destination to determine to which questionthe answer is even if the answer is received but late.

The selection procedure is a program for menu selection described in alanguage like an intermediate language, and in accordance with a flow ofoperations described in the selection procedure, display such as, forexample, image display, character string display or moving picturedisplay is provided on the screen or, in some cases, a voice message isreproduced. Further, acceptance of an operation from a subscriber orresponding processing such as switching of the display on the screen inresponse to such operation is performed.

The display/audio data include data of fonts, graphics, animations ormoving pictures for use for displaying of such an image, a characterstring or moving pictures as described above and data for a voicemessage.

The time limit information includes an effective time (responsepermission period) for which reply to contents of selection indicated bythe selection procedure identification information described above ispermitted and a time until displaying is to be automatically stopped onthe reception side when no operation is received in response to a menudisplay. When displaying is to be stopped on the receiving side, aprearranged time until a correct answer is to be broadcast is set.

Reply destination information includes communication environment settinginformation, a telephone number of the reply destination and otherinformation. The communication environment setting information includesa communication rate upon reply, presence or absence of a parity,whether or not an NMP is used, an X modem system and so forth. Thetelephone number of the reply information is used for automatic dialingwhen an answer is replied by a selection operation of a subscriber, andto the reply destination of the telephone number, such reply informationas illustrated in FIG. 10 is replied from a subscriber in accordancewith an environment set in accordance with the communication environmentsetting information.

It is to be noted that, when information relating to a program ismultiplexed in the character multiplex form, the receiving apparatus canform responding operation time instant information using timeinformation in the received information relating to a program. Inparticular, time information in the multiplexed information when aresponding operation is performed is fetched, and the time informationthus fetched is transmitted as a responding operation time instant tothe reply destination.

When information relating to a program is constructed in the form of acharacter multiplex signal as described above, the transmission rate ofinformation is very high. Accordingly, when a telephone number of areply destination and so forth are transmitted on a DTMF signal, it mustbe displayed for each digit on the screen. However, where the charactermultiplex broadcasting system is employed, reply destination informationcan be displayed at a time on the screen of the television picture tube.

It is to be noted that the application of the present invention is notlimited to a case wherein information relating to a two-way program suchas a reply destination is multiplexed in a main broadcasting signal asdescribed above. For example, the present invention can be applied to atwo-way broadcasting program wherein information representative of atelephone number of a reply destination or a response inputtingprocedure is broadcast as an image or sound by a main broadcastingsignal.

Further, while, in the embodiment described above, identificationinformation peculiar to each individual apparatus set upon production ofa television receiver designed to cope with a two-way broadcastingprogram, that is, a product number, is employed as the identificationinformation of a receiving apparatus, some other number such as atelephone number, a zip code or a registration number which is appliedupon registration of the receiving apparatus into a data base center asdescribed above may be employed as the identification information.

Having now fully described the invention, it will be apparent to one ofordinary skill in the art that many changes and modifications can bemade thereto without departing from the spirit and scope of theinvention as set forth herein.

What is claimed is:
 1. A method of interactive television broadcastingusing a two-way broadcast receiving apparatus, comprising the stepsof:receiving a broadcast signal from a broadcast side, wherein saidbroadcast signal comprises sub-broadcasting information includingdestination data representing a specified reply destination and limitdata representing specified limits for transmission of reply data, andwherein the sub-broadcasting information is constructed using adual-tone-multi-frequency signal within an audio signal band and isbroadcast in a multiplexed condition with a main broadcasting audiosignal; extracting said destination data and said limit data from saidbroadcast signal; storing said destination data extracted from saidbroadcast signal in a first memory; storing said limit data extractedfrom said broadcast signal in a second memory; storing uniqueidentification data associated with said receiving apparatus in a thirdmemory; comparing said identification data stored in said third memorywith said limit data stored in said second memory; inputting commanddata including said reply data; transmitting said reply data to apredetermined destination specified by said destination data stored insaid first memory; controlling the transmission in said transmittingstep in accordance with data input during said inputting command datastep, said reply data and said limit data; and inhibiting saidtransmission in said transmitting step from transmitting said reply datawhen in said comparing step it is determined that said identificationdata stored in said third memory does not match said limit data storedin said second memory.
 2. A method of interactive televisionbroadcasting using a two-way broadcast receiving apparatus whichtransmits a response of a user of said receiving apparatus to a two-wayprogram provided from a broadcasting station side, wherein the responseis transmitted to a predetermined reply destination by way of atelephone line, comprising the steps of:inputting information of aresponse to the two-way program; transmitting the thus inputted responseinformation to the reply destination of the broadcasting station side byway of a telephone line; providing time instant information storingidentification information allocated to said receiving apparatus;setting a time instant at which the response information is to betransmitted in accordance with the time instant information and theidentification information; transmitting the response information to thereply destination when the time instant comes; and inserting informationregarding a point of time at which the responding operation is performedinto the response information.
 3. A method of interactive televisionbroadcasting using a two-way broadcast receiving apparatus whichtransmits a response of a user of said receiving apparatus to a two-wayprogram provided from a broadcasting station side, wherein the responseis transmitted to a predetermined reply destination by way of atelephone line, comprising the steps of:inputting information of aresponse to the two-way program; transmitting the thus inputted responseinformation to the reply destination of the broadcasting station side byway of a telephone line; providing time instant information using a timecircuit; storing identification information allocated to said receivingapparatus;setting a time instant at which the response information is tobe transmitted in accordance with the time instant information from saidtime circuit and the identification information; transmitting theresponse information to the reply destination when the time instantcomes; extracting limit time information of responses to the two-wayprogram multiplexed in a broadcasting signal; storing the thus extractedlimit time information; inserting information regarding a point of timeat which the responding operation is performed into the responseinformation; discriminating from the time information whether the timeinstant at which the responding operation is performed is within apredetermined time prior to a response ending time instant which isdetermined from the limit time to responses; and setting, when theresult of discrimination provides that the time instant at which theresponding operation is performed is within the predetermined time priorto the response ending time instant, a transmission time instant for theresponse information within a predetermined time after the responseending time instant.
 4. A method of interactive television broadcastingusing a two-way broadcast receiving apparatus, comprising the stepsof:inputting information of a reply to a question or the like from abroadcasting side; transmitting the inputted reply information to thebroadcasting side by way of a telephone line; reproducingsub-broadcasting information regarding a reply destination multiplexedwith a reception signal and a telephone call origination limitinginformation multiplexed with the reception signal for limitingtransmission of the reply information, wherein the sub-broadcastinginformation is constructed using a dual-tone-multi-frequency signalwithin an audio signal band and is broadcast in a multiplexed conditionwith a main broadcasting audio signal; storing the information regardingthe reply destination and the telephone call origination limitinginformation; holding identification information peculiar to saidreceiving apparatus; comparing the telephone call origination limitinginformation and the identification information peculiar to saidreceiving apparatus with each other for discriminating whether atelephone call origination for the reply from said receiving apparatusis permitted; and inhibiting, when the result of said discriminationproves that a telephone call origination from said receiving apparatusis not permitted, transmission of the reply information to the replydestination.